The present invention relates to a process for purifying 1,1,3,4,4,6-hexamethyltetralin (hereinafter referred to as HMT).
7-Acetyl-1,1,3,4,4,6-hexamethyltetralin obtained by acetylation of HMT is used as a perfume for soap and cosmetics.
Japanese Patent Examined Publication No. 53-10057 describes a process comprising producing HMT from p-cymene, removing a solvent ethylene dichloride by distillation at atmospheric pressure, recovering the excess p-cymene under reduced pressure, thereafter obtaining HMT as a colorless distillate (purity: 95%) having a boiling point of 80.degree.-90.degree. C. at a pressure of 1 mmHg, and then recrystallizing this HMT from an equal amount of isopropanol.
Japanese Patent Examined Publication No. 63-64410 describes a process comprising removing the solvent ethylene dichloride at atmospheric pressure, recovering the excess p-cymene under reduced pressure, thereafter obtaining crude HMT with a purity of 85.7%, and then recrystallizing the crude HMT from isopropanol.
However, in the conventional processes, the purity of purified HMT is not always high and the recovery is not sufficient, probably because isopropanol is a solvent capable of easily dissolving HMT and hence the amount of isopropanol used is limited.